Vinyloxyalkylcarbamates and vinyl thioalkylcarbamates



United States Ratent thee Z,8G5,840 Patented Sept. 1'7, 1957VINYLOXYALKYLCARBAIWATES AND VINYL THIOALKYLCARBAMATES 20 Claims. (Cl.260-77.5)

This invention deals with vinyl ethers and sulfides of the structure ofone of Formulas I and II:

wherein 5 is o-phenylene or p-phenylene, A is oxygen or sulfur, Z is analkylene group of one to seven carbon atoms, n is an integer having avalue of 1 to 2, R is hydrogen, an alkyl group, an alkenyl group, abenzyl group, or a cyclohexyl group, R is either (a) an ester-formingalcohol residue, including alkyl, alkenyl, benzyl, and cyclohexyl groupswhen n is 1, or (b) a divalent glycol residue, such as an alkylenegroup, when n is 2, and R and R" each represent a member selectedindividually from the class consisting of hydrogen and alkyl groups ofone to four carbon atoms, R and R" not being hyhydrogen when all ofthree conditions exist simultaneously, namely that (1) A is oxygen, (2)R is hydrogen, and (3) Z is an alkylene chain of only one to two carbonatoms. This invention is also concerned with a process for preparingthese compounds and with polymers and copolymers formed therefrom.

This application is a. continuation-in-part of our copending applicationSerial No. 348,108, filed April 10, 1953, now abandoned.

These compounds are useful as chemical intermediates. When R ishydrogen, they are split upon being heated in the presence of a basiccatalyst to form isocyanates which are reactive and useful substances.They can undergo addition reactions at the vinyl linkage. They forminteresting polymers when treated with a free radical catalyst. Theyform interpolymers with other polymerizable vinylidene compounds. Thesepolymers and copolymershave properties which fit them for use as textilefinishing agents, in coating compositions, and as adhesives. Monomershaving large substituents are useful as resin plasticizers and asstabilizers for polyvinyl chloride.

The compounds of this invention are obtained by the reaction ofacetylene on aminoalcohols or aminomercaptans of one of Formulas III andIV:

The aminoalcohols or aminomercaptans and acetylene are reacted in thepresence of a basic catalyst to produce compounds of Formulas V and VIrespectively; thus:

IV VI The reaction is readily carried out in the presence of a smallamount (5% to 10%) of potassium hydroxide, for example, as catalyst.Acetylene is passedinto the alcohol or mercaptan, usually in an inertorganic solvent such as benzene, toluene, or high boiling ether, at toC. under pressures of 200 to 500 pounds per square inch. The vinylethers or sulfides which are thus formed are separated by distillingunder reduced pressure. An alternative procedure for making the sulfidesis to react acetylene with an aminoalkylisothiuronium salt of thegeneral Formula VII:

where the symbols are the same as above except Y is a negative anion,such as chloride, bromide, sulfate, and so on. The reaction is carriedout under the conditions substantially as just described and moreparticularly disclosed in application Serial No. 522,397, filed on evendate herewith in the hands of a common assignee. The thiuronium saltsare made by heating in an alcohol, such as ethanol, at reflux (60 to 80C.) a mixture of approximately equimolar amounts of thiourea and thecorresponding chloride, bromide, or the like having the Formula VIIa:

Vila R As typical aminoalcohols there may be used 4-amino- 4methylpentanol, 4-amino-4-methyl-2-pentanol, 2- amino-Z-methylpropanol,2-amino-2-ethylpropanol, 2-N- methylamino 2 methylpropanol, 2 Nbutylamino 2 methylpropanol, 2-N 2 ethylhexylamino 2 methylpropanol,Z-N-dodecylamino-Z-methylpropan l, Z-N-allylamino-Z-methylpropanol,2-N-benzylamino-Z-methylpropanol, 2N-cyclohexylamino-Z-methylpropanol,2-arnino- 2-methylbutanol, Z-N-methylamino-Z-methylbutauol, 2-N-benzylamino-Z-methylbutanol, 2-N-cyclohexylamino-2- methylbutanol,4-aminobutanol, 4-N-methylaminobutanol, S-arninopentanol,S-N-methylaminopentanol, 7- amino 3,7-dimethyloctanol,Z-ethylamino-l-phenylethanol, 2-allylamino-l-hexylethanol. Typicalaminomercaptans that may be used include Z-aminoethylmercaptan,3-aminopropylmercaptan, 2-amino-l-methylethyltnercaptan, andZ-arninophenylmercaptan. Typical isothiuro- 'nium salts that may be usedin the alternative procedure are N-methylaminoethylisothiuroniumchloride and 2- aminoisobutylisothiuronium chloride.

The aminoalkyl vinyl ethers or sulfides of Formulas V and VI thusobtained are reacted with an alkyl halocarbonate, sometimes also termedan alkyl haloformate, XCOOR, where X is chlorine or bromine and R is analcohol residue forming an ester. R may be an aliphatic hydrocarbongroup, including such radicals as methyl, ethyl, propyl, butyl, octyl,Z-ethylhexyl, isononyl, dodecyl, cetyl, octadecyl, tetracosyl, allyl,methallyl, undecenyl, and oleyl, or aralkyl such as benzyl andmethylbenzyl, or cycloalkyl, such as cyclohexyl, cyclopentyl, andmethylcyclohexyl, or a hydrocarbon chain interrupted by oxgen or sulfur,as in ethoxyethyl, butoxyethyl, phenoxyethyl, and the like, or aneutrally substituted group such as p-chlorobenzyl, p-nitrophenyl,chloroethyl, nitroethyl, etc.

The reason Why R and R" cannot be hydrogen in certain ethers is the needfor providing steric hindrance to the nitrogen atom nearby when thisnitrogen carries a hydrogen atom in order to prevent cyclization. Thissteric hindrance is surprisingly unnecessary when sulfides are reacted.

- There are several, preferred subclasses of alkyl halo- V 2,806,840 V acarbonates in which R is an important substituent. For example, R isdesirably an alkyl group of one to four carbon atoms, particularly whenthe vinyloxyalkylcarbamates or vinyl thioalkylcarbamates are to beconverted to isocyanates, in which case R must be hydrogen and R shouldbe relatively small for economic reasons. On the other hand in somecases where it is desired to separate out the isocyanate derivative, itmay be desirable to have R rather large. Then a carbon content of 12to'24'carbon atoms becomes advantageous, another preferred class beingthus constituted.

The group R also takes the forrnof a divalent group which formsdiesters. For example, R may be an ethylene or propylene chain, formingan alkylene bischlorocarbonate. It may also be the residue of apolyglycol, such as ethylene diglycol, propylene diglycol, diethylenetriglycol, thiodiglycol, and the like.

. aphids on bean plants. At 24 hours the kill was 74% The reaction ofhalocarbonate and aminoalkyl vinyl V ether or sulfide is'performed in'the presence of an acceptor fl t e hydrogen h id whi h is split o t.Excess aminoalkyl vinyl ether r s fide 211 used for this purpose, anamine hydrohalide being then formed. There may also be used-sodiumcarbonate, sodium bicarbonate, potassium carbonate, sodium hydroxide, orthe "like, 191' pyridine, trimethylamine, or a other unreactive tertiaryamine. e I

The reaction is carried out at temperatures from 0 to 100 .C., desirablyin the presence of-inert organic solyent such as benzene or toluene.Ifexeess amine is used, amine hydrochloride forms as a precipitate andisfiltered off. If an inorganic base is ,used, the salt formed is con-'veniently taken up in water and thus separated. The organic solvent isstrippe'dofi to leave the product. This may be purified in conventionalways, as by distillation.

Polymerization of monomers is best accomplished with the aid of anazo-type of free radical catalyst. From 0.05% to 2% of one or more ofthese is generally used with temperatures of polymerization between 50and 80 C.

The a zo catalyst are compounds in which the .-N-.'=N group is attachedto aliphatic carbon atoms, at least one of which is tertiary. In theseone of the carbon atoms bonded to the tertiarycarbon atom has itsremaining valences satisfied by at least one element from the classconsisting of oxygen and nitrogen. Typical catalysts areazodiisobutyronitrile, azodiisobutyramide, dimethyl, diethyl, or'dibntyl azodiisobutyrate, 'azobis(a,'y-dimethyl- There was no foliageinjury.

Example 2 To a stirred mixture of 23 parts of VZ-aminoisobutyl vinylether, 16.6 parts of potassium carbonate, 40 parts of Water, and 44parts of benzene there is added over a 35 minute period 23.8 parts ofethyl chlorocarhonate, The heat of reaction causes the mixture to boilunder reflux. Stirring is continued for 1.5 hours. Addition of 100 partsof Water is made and the layers are separated. The organic layer iswashed with water, dried, and stripped of volatile material "by heatingunder reduced pressure to about 100 C. at 20 mm. The resulting oil isthen distilled. At 107 to 107.5 C,/ 13 a product is obtained in anamount of 35 parts, which corresponds in composition to ethylN-(vinyloxy-tert-butyl)carbamate.

Example 3 A portion of 10 parts of ethyl N-(vinyloxy-tert-butyl)carbamate is mixed with 0.2 part of dimethyl azodiisobutyrate and placedin a pressure container. Air is displaced therefrom with nitrogen. Thecontainer is led n heated at C. iq 48 hou s- A viscous 7 productresults. It is taken up in methanol and transvaleronitrile),azobis(a-methylbutyronitrile), azobis(ozmethylvaleronitrile), dimethylor diethyl azo'bismethylvalerate, and the like. These catalysts are alsouseful in preparingcopolymers.

Further details of the preparation of compounds of this invention aregiven in the following illustrative examples,

in which parts are by weight:

. Example 1 A solution is prepared of 575 parts of l aminoisobutylferred to another c n a n r. in which solvent n sidual monomer r r mo byh at ng nde educed pressur There results a very viscous resin. This isuseful for y ng h p op r f alkyd coating res n It is 1 9 useful informulat ng d e par i ularly hen: la s is. involved, as the compound hasa high degree of adhesion'to glass.

Example 4 The r xed w h i rin 115 pa ts of Z-aminQ: is l ny e 0 Pa ts ob nze e. 42 Parts o potassium c rb t an 2 0 P r of w er. Therein i s w yadded die hyle gly ol bi ch or carbona e in an a ount of 11.6 pa e ea ofreac i n is allowe t a m up the ixt e nd he r action m tur is stirredfor an hour. Layers are permitted to form and a p t The rganic laye iWash d with water. dried, and heated under reduced pressure to leaye anoil, which corresponds very closely in composition to that equ ed -f r ey1 ne y ol b s(: -(vinylQxy tet -buty ca bama 4 a In the same way theremay be used ethylene bischlorocarbonate, propylene bischlorocarbonate,thiodiethylene bischlorocarbonate, and the like to form his (vinyloxyvinyl ether in 1880 parts .of dry benzene. To this solution,

while it is stirred and cooled, there is slowly added over a two hourperiod 271 .parts of ethyl .chlorocarbonate. The temperature during thistime is held between 0 and 10 C. The reaction is stirred for another 1.5hours and filtered to remove amine hydrochloride. This salt is rinsedwith benzene and dried in vacuo. The benzene filtrate is washed withcold, saturated sodium bicarbonate solution, dried over magnesium'sul-fate,'and' filtered. Benzene is taken oif under reduced pressure toyield an oil, which is distilled to give 367 parts of ethyl N(vinyloxy-tert-butyl)carbamate. This product distills at 70 C ./1'.2 mm.or 55 C./0.4 mm. It has a refractive in ex. l of 1- 75.

This compound is useful as an insecticidal agent, being a stomach poisonand also having contact action. it was compounded 'into'a 5% dust whichwas applied to bean plants infested with bean beetle larvae. It gave a1.00% kill after 24 hours, A spray was preparedwiththe abovealkylcarbamates). These compounds-polymerize to form gels.

Example 5 A mixture is prepared from 101 parts of Z-N-methylaminoethylvinyl ether, 300 parts of toluene, parts of water, and 83 parts ofanhydrous potassium carbonate. This is cooled to -l0 to 0 C. and 94.5parts of methyl chlorocarbonate is carefully added over an hour, whilethe temperature is maintained between 10 and 0 C. The mixture isfiltered and the salt cake is washed with toluene. The organic layer iswashed with cold brine, dried over magnesium sulfate, and stripped ofvolatile material under reduced pressure. This product is purified'bydistilling under reduced pressure. The fraction coming over at 108 C./30mm., 118 parts, corresponds This fraction contains by analysis 8.8% ofnitrogen (theory 8.8%). It has an index of refraction at 22 C.

of 1.4478. It is a water-white, pleasant smelling liquid, which isinsoluble in cold water, but which hydrolyzes particularly in hot waterto a water-soluble product. This hydrolysis affects only the ester groupand is not noted with higher alkyl carbamates.

A portion of parts of this product is mixed with 0.2 part of dimethylazodiisobutyrate. The mixture is heated under nitrogen at 75 C. foreight hours. The resulting product, amounting to 9.8 parts, is a lightyellow viscous gum. Monomer is removed by heating in vacuo. Theresulting polymer is soluble in methanol and in aqueous methanol. It hasa molecular weight of about 50,000, as indicated by osmotic pressuremeasurements. This indicates about 300 units in the polymer chain anddemonstrates how the monomers of this invention can form high polymers.This is in contrast with such previously known carbamates as allyl,which exhibit low degree of polymerization.

This polymer of methyl N-methyl-N-(2-vinyloxyethyl)-carbainate has beenfound very desirable in sizes for fibers and fabrics of such syntheticpolymers as nylon. For example, an aqueous 3.5% solution of this polymerprovides an excellent warp size for pylon, this polymer having adhesionto this material and remaining watersoluble thereon. 1

Example 6 The procedure of Example 5 is applied to the reaction ofZ-N-rnethylaminoethyl vinyl ether and allyl chlorocarbonate, 120.5 partsbeing used in place of the above methyl ester. The fraction distillingat 101 to 103 C./1.5 mm. is allyl N-vinyloxyethyl-N-methylcarbamate. Ithas a refractive index of 1.4640 at 25 C. and contains 58.3% of carbon,8.1% of hydrogen and 7.6% of nitrogen. Corresponding theoretical valuesare 58.4%, 8.12%, and 7.57%, respectively.

A portion of 10 parts of this allyl ester is mixed with 10 parts ofdimethylformamide. There is added 0.6 part of dimethyl azodiisobutyrateand the mixture is heated under nitrogen at 70 to 75 C. for six hours. Asolution of polymer results. This polymer when heated at 150 C. yieldsan insoluble, cross-linked product.

Monomers containing the allyl group can be polymerized to solublepolymers when a high concentration of catalyst is used or thepolymerization is eifected in the presence of chain transfer agents suchas mercaptans. The soluble polymers become cross-linked when heated :at120 to 180 C. or when air-dried in the presence of a cobalt compound.

Example 7 The procedure of Example 6 is followed with substitution of115 parts of N-vinyloxyethyl-N-ethylamine and 108.5 parts of ethylchlorocarbonate. There results a carbamate, ethyl Nvinyloxyethyl-N-ethylcarbamate, which distills at 75 to 80 C./2.5 mm.This product has a molecular weight of 187 and contains 7.5% ofnitrogen. It has a refractive index of 1.4432 at 20.5 C.

When treated with 0.5% to 2% of an azo catalyst, it forms a polymerwhich is soluble in alcohols and which has a high molecular weight.

Example 8 The procedure of Example 6 is applied to 101.5 parts ofN-vinyloxyethyl-N-methylamine and 168.5 parts of benzyl chlorocarbonate.The resulting product distills at 125-127 C./0.5 mm. and correspondsincomposition to benzyl N-vinyloxyethyl-N-methylcarbamate. It has amolecular weight of about 235 and contains 6.0% of nitrogen (theory5.96%). It has a refractive index of 1.5253 at 25 C.

This compound forms polymer in low yields, but enters into copolymersreadily.

Example 9 The procedure of Example 6 is applied to 164 parts of vinylN-cyclohexylaminoethyl ether and 94.5 parts of methyl chlorocarbonate.The product is methyl N-vinyloxyethyLN-cyclohexylcarbamate, distillingat 93 C./ 0.3 mm. It has a refractive index of 1.4781 at 222 C.

This compound when treated with 0.5 to 2% of dimethyl azodiisobutyrateat 75 C. forms a polymer which is soluble in methanol, ethanol, acetone,or toluene, but is insoluble in petroleum ether, although the monomer issoluble therein. Petroleum ether may, therefore, be used to extractmonomer from the polymer. The solutions of polymer deposit hard, glossycoatings and can serve as lacquers or enamels.

Example 10 The procedure of Example 6 is applied to the reaction of108.5 parts of ethyl chlorocarbonate and 199 parts of vinylN-(2-ethy1hexyl)aminoethyl ether. The product is, however, obtained as astripped residue. It has a molecular weight of about 270. It is solublein hydrocarbon solvents and has plasticizing action. It corresponds incomposition fairly closely to ethyl N-vinyloxyethyl-N-(Z- ethylhexyl)carbamate.

Example 11 In the same way there are reacted 191 parts of vinylN-u-methylbenzylaminoethyl ether and 94.5 parts of methylchlorocarbonate. The product is methylN-vinyloxyethyl-N-a-methylbenzylcarbamate. A portion of residue isdistilled at about 113 C./ 0.5 mm. The distillate has a refractive indexof 1.5140 at 20 C. It has a molec- There are reacted by the aboveprocedure vinyl 5-aminopentyl ether and ethyl chloroc-arbonate inequimolar amounts. The product-is distilled at 111 to 114 C./1 mm. in a65% yield. It has a refractive index of 1.4579 at 17 C. and a molecularweight of 200. It corresponds in composition to ethylS-N-vinyloxypentylcar- =bamate.

This compound polymerizes under the influence of azo catalysts. Thepolymers are soluble in toluene and alcohols.

Example 13 There are mixed 66 parts of dodecylN-methyl-N-vinyloxyethylcarbamate and 33 parts of octa'decyl N-m6thyl-N-vinyloxyethylcarbamate. The mixture is treated with one part of dimethylazodiisobutyrate and heated under nitrogen at 75 C. for 16 hours. Aviscous polymer forms. it is soluble in hydrocarbon solvents andpetroleum oils. In a wax-containing Pennsylvania motor oil it depressesthe pour point at concentrations from 1% ,to 5

Copolymers are readily formed from a vinyloxyalkylcarbarnate of thisinvention and another vinylidene compound which is polymerizable withfree radical catalysts. While polymerizable monovinylidene compounds arepreferred, there may also be used polyvinylidene compounds. These, ofcourse, promote cross-linking with its attendant effects. Useful freeradical-polymeriza-ble vinylidene comonomers include acrylates,meth-acrylates, acrylonitrile, methacrylonitrile, acrylamides,methacrylami'des, styrene, vinyl esters, etc.

to dissolve the salts. The benzene layer is Washed wi carbonate andWater until the wash water is neutral. The benzene solution isconcentrated and the residual oil distilled at reduced pressure to give65 grams of colorless product, ethyl N-2-(vinylthio) ethyl carbamate, inthe fraction boiling at 89 to 92 C./O.5 mm. Hg. The product has asulfury-ester odor and contains by analysis 48.05% C; 7.35% H; 7.93% N;and 18.17% S; the calculated values are 48.0% C; 7.43% H; 8.0% N; and18.3% S. The infra-red spectrum contains a peak at 1590 cm.charactertistic of vinyl sulfide and peaks at 3330, 1530, 960 and 873cmrcharacteristic of hydrogen on nitrogen thus clearly establishing thepresence of the vinyl group.

Example 23 A casting in the form of a sheet is prepared by thepolymerization of 99.5 parts of methyl methacrylate with 0.5 part of theproduct of Example 22 in the presence of 0.02 part of benzoyl peroxide.The resultant polymer sheet is clear and colorless. When subjected to atemperature of 200 C. for several hours, it shows a greatly decreasedrate of weight-loss as compared to a homopolymer of methyl methacrylate,the sulfide group exerting a definite thermal-stabilizing action.

One of the important uses of the compounds of this invention is aschemical intermediates to form isocyanates. When the ester group issmall, an alcohol is distilled from the isocyanate. When this group islarge or when the ester group is bifunctional, the isocyanate can bedistilled from the reaction mixture containing an alkaline catalyst. Theester formed with the diethylene glycol group in Example 4 and theequivalent compounds there discussed are suitable for yieldingisocyanates in this way. Biscarbamate and basic catalyst, such as sodiummethoxide, sodium oxide, or sodium hydroxide, are heated at 150 C. to200 C. and the resulting isocyanate is distilled off, under reducedpressure, it so desired.

Insecticidal tests with methyl N-(vinyloxyethyl)-N- methylcarbamate haveshown insecticidal action for this compound. A so-called emulsionconcentrate was prepared with this compound, aromatic solvent, and anonionic, oil-soluble wetting agent. The concentrate was diluted withwater to give a 1:400 dilution of this compound. The spray was appliedto bean plants infested with aphids. A 50% kill was obtained in 24hours.

Another valuable action of the carbamates of the present invention whichhave groups of sufiicient size to ensure solubility in organic solventsis in the field of plasticizers. For example, when ethylN-vinyloxyethyl- N-Z-ethylhexylcarbamate is milled into such vinylpolymers as those based on vinyl chloride, including vinylchloride-vinyl acetate copolymers, at 2% to 40% either as a primaryplasticizer or better in combination with other plasticizers, it exertsa definite softening efiect, promoting flexibility at reducedtemperatures. 7

The vinyloxyalkylcarbamates are of especial interest because of themodifying influence of the carbamate group on the vinyl ether radical.Even though the carbamate and vinyl groups are separated by an alkylenechain of as much as eight carbon atoms between the ether oxygen andcarbamate nitrogen, the influence of the carbamate group remains acontrolling factor. This is best illus rated by the fact thatvinyloxyalkylcarbamates are polymerized with free radical catalysts. Thepresence of 1% to 2% of an azo free-radical catalyst, such as dimethylazodiisobutyrate, gives over 90% conversion to polymer in 16 hours. Incontrast vinyl butyl ether, as a typical 'vinyl alkyl ether, is scarcelyaffected by free radical catalysts. Even with amounts up to 10% ofazodiisobutyroni- The vinyl alkyl It is to be understood that changesand variations may wherein is selected from the group consisting of 0phenylene and p-phenylene, A is selected from the group consisting ofoxygen and sulfur, Z is an alkylene group of one to seven carbon atoms,n is an integer having a value of 1 to 2, R is a member of the classconsisting of hydrogen, alkyl, alkenyl, benzyl, and cyclohexyl groups, Ris selected from the class consisting of (a) alkyl, alkenyl, benzyl, andcyclohexyl groups when n is l, and (b) divalent glycol residues when nis 2, and R and R" each represent a member selected individually fromthe class consisting of hydrogen and alkyl groups of one to four carbonatoms, R and R not being hydrogen when all of three conditions existsimultaneously, namely that (l) R is hydrogen, (2) A is oxygen, and (3)Z is an alkylene chain of only one to two carbon atoms.

2. A polymer of a compound of claim 1.

3. A copolymer of a compound of claim 1 with another freeradical-polymerizable vinylidene compound.

4. A copolymer according to claim 3 in which the vinyl idene compound isa monovinylidene compound.

5. A compound of the structure wherein R is an alkyl group of 1 to 24carbon atoms.

6. A polymer of a compound of claim 5. 7. A compound of the structureCH: CH =CH-OCHz(ilNH-CO OCH:

8. A compound of the formula ([JHa "I CHFOHOOHr-C-NHC o o ornonio CH3 J29. A compound of the formula CHz=CHO-CHOHz-NCOOR wherein R and R arealkyl groups of 1 to 18 carbon atoms.

10. A polymer of a compound of claim 9.

11. As a composition of matter, an ester having the structure of theformula where 45 is selected from the group consisting of a-phenyleneand p-phenylene, and R is an alkyl group having 1 to 4 carbon atoms.

12. A polymer of an ester as defined in claim 11. 13. As a compositionof matter, an ester having the structure of the formula RICHFOHOZC|}NHOOOR where Z is an alkylene group of one to seven carbonatoms, R is an alkyl group of 1 to 4 carbon atoms, R"

'j nqxmr s tsw l l iiiPf aim'i w h, v V UNITED M T -PAT ENT 17. As acomposition of matter, ethyl N'=2-(Viny1thio)-- V phenyl carbamate" 7 7=.6. 4- pai g 1, 5.2; 18. A copolymer of an ester as defined in claim 17with 10 T methyl methacrylate.

1. AS A COMPOSITION OF MATTER, AN ESTER SELECTED FROM THE GROUPCONSISTING OF THOSE HAVING THE STRUCTURE OF FORMULAS 1 AND 11: